MCP, MCP server
Agent Guardrail MCP Server
Agent Guardrail MCP Server, an MCP server listed in the PlugVet directory.
Compatibility: Not stated.
Grade B
Minor issues only, no Medium or High. Worth a quick look at the findings below before installing.
Not a guarantee. A hygiene check of the source at the commit shown, not a security audit.
Rescanned at commit 9f74ba7d4f31, unchanged since the check below.
NETWORK_NO_FIXED_HOST SECRETS_PATH_UNCONFIRMED PERMISSION_SHELL_DECLARED SECRETS_ENV_READ
Why this grade
- NETWORK_NO_FIXED_HOST Low
Makes a network call whose host is not written as a fixed address.
mcp_guardrail_http.py, line 62
with urllib.request.urlopen(req) as resp: - SECRETS_PATH_UNCONFIRMED Low
The Secrets check reports a credential or environment file, but no quoted line shows a recognisable path.
mcp_guardrail_http.py, line 29
GUARDRAIL_API_KEY = os.environ.get("GUARDRAIL_API_KEY", "") - PERMISSION_SHELL_DECLARED Note
Runs shell commands, and the manifest or description says so.
examples/decorator.py, line 13
return subprocess.run(cmd, shell=True, capture_output=True).stdout - SECRETS_ENV_READ Note
Reads an environment variable whose name contains KEY, SECRET, TOKEN, PASSWORD or CREDENTIAL.
mcp_guardrail_http.py, line 29
GUARDRAIL_API_KEY = os.environ.get("GUARDRAIL_API_KEY", "")
Any High, or two or more Medium findings, give D. One Medium gives C. Low findings or a security Note give B. Each code names a finding behind the letter.
Grades are a hygiene check of the source at the commit shown, on the date checked, not a security audit or a guarantee. The free directory grades are automated. Before release, a PlugVet engineer reviews every paid report and any grade we hold back, including all F grades, against the source code and the evidence we quote.
What was checked
Plain notes from the hygiene checks.
Permissions
Note
requests shell access. The manifest names this permission.
PERMISSION_SHELL_DECLARED
examples/decorator.py, line 13
return subprocess.run(cmd, shell=True, capture_output=True).stdout
Install and update
Pass
No install-time script found, and dependencies are pinned or absent.
Network
Concern
can reach a host that is not written as a fixed address.
NETWORK_NO_FIXED_HOST
mcp_guardrail_http.py, line 62
with urllib.request.urlopen(req) as resp:
Secrets
Concern
reads a credential or environment file.
SECRETS_ENV_READ SECRETS_PATH_UNCONFIRMED
mcp_guardrail_http.py, line 29
GUARDRAIL_API_KEY = os.environ.get("GUARDRAIL_API_KEY", "")
agent_guardrail/billing.py, line 82
self._api_key = os.environ.get("BLOCKONOMICS_API_KEY", "").strip()
agent_guardrail/billing.py, line 83
self._webhook_secret = os.environ.get("BLOCKONOMICS_WEBHOOK_SECRET", "").strip()
Show more
agent_guardrail/billing.py, line 398
return bool(os.environ.get("STRIPE_SECRET_KEY", "").strip())
agent_guardrail/billing.py, line 424
secret_key = os.environ.get("STRIPE_SECRET_KEY", "").strip()
agent_guardrail/billing.py, line 486
secret_key = os.environ.get("STRIPE_SECRET_KEY", "").strip()
agent_guardrail/billing.py, line 487
webhook_secret = os.environ.get("STRIPE_WEBHOOK_SECRET", "").strip()
agent_guardrail/policy.py, line 12
"target_denylist": ["/etc/*", "/root/*", "*.env"],
agent_guardrail/policy.py, line 303
"target_denylist": ["/etc/*", "/root/*", "*.env", "*.key", "*.pem"],
agent_guardrail/policy.py, line 317
"*.env",
agent_guardrail/policy.py, line 334
"target_denylist": ["*.env", "*.key", "*.pem"],
agent_guardrail/proxy.py, line 143
_billing_api_key = os.environ.get("BLOCKONOMICS_API_KEY", "").strip()
.gitignore, line 16
env/
README.md, line 240
"target_denylist": ["/etc/*", "*.env", "*.key"], # These targets always denied
docs/nlnet-application.md, line 42
5. Target denylist matching - deny if the target path or URL matches a forbidden pattern (e.g., `/etc/*`, `*.env`, `*credentials*`)
Agent instructions
Pass
No instruction to ignore earlier instructions or to hide a step.
Obfuscation
Pass
No encoded or minified payload found.
Licence
Pass
A licence file is present (LICENSE).
Maintainer activity
Pass
The latest commit is within the last 365 days.
Note
Hygiene check of commit 9f74ba7d4f31. requests shell access. The manifest names this permission. can reach a host that is not written as a fixed address. reads a credential or environment file.
Date and source
Date checked:
github.com
Commit graded: 9f74ba7d4f31daa06aae9fe374d6414e88372573
This link goes to the original host. PlugVet does not host or check what you download from there, and installing it is your own decision and risk.